92 research outputs found

    Formulation of the membership function and determination of the input of fuzzy loads in the structural fuzzy analyzing problem

    Get PDF
    The fuzzy analyzing process consists of different steps. In this paper, the author considers only the method for formulation of the membership function of fuzzy loads acting on the structure. Based on the membership function of fuzzy loads, the combinations of deterministic of the regression analyzing process will be determined. The membership function of fuzzy loads is selected by the triangular membership function. It is in conformity with the concept on selection of loads in the design standards. The combination of inputs for the analyzing process will be determined, based on the number of present times of the value of input parameters (including the deterministic parameters, fuzzy parameters and the random ones) in the schema of analysis. The number of present times of input parameters is either proportional to value of the corresponding membership function or to the value of the probabilistic density function. A method for determining the appropriate combination of deterministic inputs so that each input parameter will present only one time in each combination is proposed. To illustrate the proposed method, an example on the determination of input combinations of tornado's velocity in Vietnam is presented

    A METHOD FOR TECHNICAL DIAGNOSIS OF CONSTRUCTION

    Get PDF
    Non

    Ocular Surface Reconstitution

    Get PDF

    A new method for determination of the reliability index of distributed parameter systems

    Get PDF
    In this paper, a method to determine the reliability - index of distributed systems is proposed. By the new method, instead of finding jointly probability depending on multi - conditions of inequalities one can find probability depending on only one inequality and no requiring to know jointly density function of basic variables. Therefore, it is very favourable for the calculation of the reliability - index of mechanical systems with distributed parameter. For illustrating the proposed method, a simple example is considere

    An extension of the E. Melan's shakedown theorem of the elasto-plastic structure

    Get PDF
    Non

    On the problem of optimal structure design subjected to regular lifetime criterion

    Get PDF
    The objective function of problem of optimal structure design can be chosen differently. For example the objective function can be the weight, the net cost, the regular resistance, the regular reliability, an so on. In this paper the problem of optimal structure design, subjected to regular lifetime condition for all elements is considered. The author sets up the problem, proposes an iterative method for solving and apply the obtained results to a simple example

    A variable separation method for the calculation of the reliability of construction

    Get PDF
    In this paper, a variable separation method for determining the reliability of construction is proposed. Therefore, the reliability is a multiplication of two probabilities: The probability of the occurrence of load and the probability of construction in the condition the load has a determined value

    Formation of secondary nonsulfide zinc ore in Cho Dien Pb-Zn deposits

    Get PDF
    In Viet Nam, non-sulfide zinc ore in the Cho Dien deposit has been exploited for a long time. Up to the present, zinc ore remains the major exploited ore in Cho Dien. There are numerous studies of Pb-Zn ore in Cho Dien. However, most of the studies have dedicated only to description of mineralogical and chemical composition of Pb-Zn ore. There has been no publication on this non-sulfide zinc ore. Based on the mineralogical studies, the content of Pb and Zn in groundwater determined by reflective microscope, SEM, EPMA and ICP-MS methods, the study explained the formation of secondary non-sulfide zinc ore in the Cho Dien deposit. Strong weathering process makes the upper part of ore bodies completely oxidized. Difference in geochemical behavior of lead (Pb) and zinc (Zn) in the oxidation process of Pb-Zn ore is the reason to form non-sulfide zinc ore in the Cho Dien deposit. Oxidation of primary Pb-Zn ore is mainly sphalerite, pyrite, galena minerals which creates a low pH environment and transforms of zinc from immobile (sphalerite - ZnS) to mobile (Zn2+) and retained in solution under acid pH conditions whereas lead has the tendency to form soluble minerals (anglesite, cerussite). The acid neutralization actions of the surrounding rocks make zinc precipitate, to form secondary non-sulfide zinc minerals.ReferencesAndreas Nuspl, 2009. Genesis of nonsulfide zinc deposits and their future utilization (www.geo.tu-frei berg.de/oberseminar/OS_09/Andreas_Nuspl.pdf.Boland M.B., et al., 2003. The Shaimerden supergene zinc deposit, Kazakhstan: Economic Geology, 98(4), 787-795.Chau N.D., Jadwiga P., Adam P., D.V. Hao, L.K. Phon, J. Paweł, 2017. General characteristics of rare earth and radioactive elements in Dong Pao deposit, Lai Chau, Vietnam, Vietnam J. Earth Sci., 39(1), 14-26.Dao Thai Bac, 2012. Characteristics and distribution law of lead-zinc metallogenic fomations in Viet Bac region. Doctoral thesis.Heyl A.V., Bozion C.N., 1962. Oxidized zinc deposits of the United States, Part 1. General Geology: U.S. Geological Survey Bulletin 1135-A.Hoa T.T., et al., 2010. By-products in lead-zinc and copper ores of Northeast Vietnam. J. Sci. of the Earth,  289-298 (in Vietnamese).Hoang Minh Thao, Tran Thi Hien, Dao Duy Anh, Pham Thi Nga, 2017. Mineralogical characteristics of graphite ore from Bao Ha deposit, Lao Cai Province and proposing a wise use. Vietnam J. Earth Sci., 39(4), 324-336.Jurjovec J., et al., 2002. Acid neutralization mechanisms and metal release in mine tailings: A laboratory column experiment: Geochimica et Cosmochimica Acta, 66, 1511-1523.Large D., 2001. The geology of non-sulphide zinc Deposits - an Overview: Erzmetall, 54(5), 264-276.Maria Boni, 2003. Nonsulfide Zinc Deposits: a new - (old) type of economic  mineralization. Society for geology applied to mineral deposits (SGA) News, Number 15. https://www.e-sga.org/fileadmin/sga/newsletter/news15/art01.html.McPhail D.C., et al., 2003, The geochemistry and mobility of zinc in the regolith: in Roach, I.C., ed., Advances in Regolith, 287-291.Murray W. Hitzman, et al., 2003. Classification, genesis, and exploration guides for non-sulfide zinc deposits: Economic Geology, 98(4), 685-714.Nguyen V.P., 2013. Wet tropical wethering in Viet Nam. Natural Science and Technology Publisher.Nicola Mondillo, 2013. Supergene Nonsulfide Zinc-Lead Deposits: The Examples of Jabali (Yemen) and Yanque (Peru). Doctoral thesis.Nordstrom D.K., Alpers C.N., 1999. Geochemistry of acid mine waste. Review in Economic Geology, the environmental geochemistry of ore deposits/Eds. G.S.Plumlee, M.J. Logsdon. Part A: Processes, techniques, and health issues, 6A, 133-160.Reynolds N.A., et al., 2003. The Padaeng Supergene Nonsulfide Zinc Deposit, Mae Sod, Thailand. Economic Geology, 98(4), 773-785.Sangameshwar S.R., Barnes H.L., 1983. Supergene Processes in Zinc-Lead-Silver Sulfide Ores in Carbonates: Economic Geology, 78, 1379-1397.Stumm W., Morgan J.J., 1996. Aquatic Chemistry, Third Edition. John Wiley Sons, New York, NY.Takahashi T., 1960. Supergene alteration of zinc and lead deposits in limestone: Economic Geology, 55, 1083-1115.Thornber M.R. and Taylor G.F., 1992. The mechanisms of sulphide oxidation and gossan formation, in: Butt, C.R.M., and Zeegers H., (Eds.)., Regolith exploration geochemistry in tropical and subtropical terrains, in Govett G.J.S., ed., Handbook of exploration geochemistry: Amsterdam, Elsevier, 4, 119-138.Tran Trong Hoa, 2005. Potential assessment of By- products in lead-zinc and copper deposits of   Northeast Vietnam. Final report.Tran Tuan Anh, 2010. Studying accompanying component in the types of potential deposits of basic metals and precious - rare metals of north Viet Nam to improve the efficiency of mining and environmental protection. Final report. KC.08.24/06-10.Tran Tuan Anh, et al., 2011. Mineralogical and geochemical characteristics and forming conditions of lead - zinc deposits  in Lo Gam structure, northern Vietnam. J. Sci. of the Earth, 33(3DB), 393-408 ( in Vietnamese).Vito Coppola et al., 2009. Nonsulfide zinc deposits in the Silesia - Cracow district, Southern Poland. Springer Link, 44, 559-580.Vito Coppola, et al., 2007. Non-sulfide zinc deposits in Upper Silesia, Southern Poland. Proceeding of the Ninth Biennial SGA Meeting, Dublin, 1401-1404.Williams P.A., 1990. Oxide zone geochemistry: Ellis Horwood Ltd., Chichester, UK, 286p. 
    corecore